GB2423408A - Identifying audiovisual apparatus and associated methods and content stored on data carriers - Google Patents

Abstract

Embodiments of the present invention relate to apparatus, methods and data carriers associated with the playback of audiovisual content. For example, in one embodiment, the apparatus is for playing audiovisual content, which is stored on a storage medium (122), the apparatus comprising a processor (105) and a memory (112) storing identification data (140), which is capable of identifying the apparatus and which is readable by the processor (105) under the control of the content. There are many potential uses for the identification data (140). For example, the identification data can be used in a determination of whether or not the apparatus is known to comply with a format specification, for example the DVD-Video format specification. On the basis of the determination, different content, or logic relating to the content, may be replayed. Another exemplary use of the identification data is to determine whether or not an apparatus has the capability to replay certain content; for example, the determination leading to a user only being offered a choice of selecting content that can replay on the apparatus.

Description

Audiovisual Apparatus, Methods and Data Carrier The present invention

relates to apparatus, methods and data carriers associated with the playback of audiovisual content. In particular, but not exclusively, embodiments of the present invention relate to the ability to identify, and use the identity of, audiovisual playback apparatus.

For many years, VHS-video tape players have been the equipment of choice for consumers for both replaying pre-recorded content, such as movies, and recording content from terrestrial, cable and satellite broadcasts. Nowadays, DVD-Video optical disc players, or simply DVD players, have supplanted VHS-video tape players as the most popular audiovisual playback and recording equipment. In future, high definition optical disc players, for example Blu-ray or I-ID-DVD players, may replace DVD-Video. In addition, or alternatively, holographic versatile disc (HVD) may become widespread. It is expected that other storage formats and other systems will arise from time to time; some relying on optical disc and others relying on other kinds of media, for example magneto-optical, magnetic, solid state or the like.

All the aforementioned technologies typically have in common a format specification, which defines the physical and logical formats of the respective recording medium. To a large extent, the commercial success of a format depends on consumers being able to buy equipment from multiple sources, which increases consumer choice and causes price competition and, hence, reduction Bespoke formats, that have been restncted to one or only a few sources, have tended to lead to higher cost of ownership and less widespread commercial success.

The VHS-video format specification is predominantly a physical specification, which defines the VHS tape dimensions and magnetic and mechanical characteristics and the recorded data densities, track orientation, pitch and width. All VHS video players should be able to write data to VHS videotape in a manner that enables the data to be read by any other VHS video player Similarly, the DVD-Video format specification includes a physical format, specifying the characteristics of a DVD-Video disc and how the information is stored on a disc. In addition, the DVD-Video format specifies a range of navigation commands and parameters. This is because, unlike VHS-video, which is a sequential playback format, DVD-Video permits a relatively high degree of interactivity and random access functionality. For example, a typical, pre-recorded DVD offers an interactive menu system, sound configuration options, the ability to playback various different items of audiovisual content in any selected order and even games. The commands are similar to computer CPU instructions insofar as they control the processing unit of a DVD player. Unlike a computer, however, the command set of a typical DVD player is substantially limited to logic that facilitates user selection and playback of audiovisual content. In particular, a typical DVD player is unable to generate audiovisual content dynamically. In other words, all content that can be replayed is pre- authored and stored on the DVD-Vidco optical disc in accord with the DVD- Video format

specification.

It is expected that future formats and respective players, for example Blu-ray and HD-DVD optical disc players, will have additional functionality that enables the players to generate text and graphics from program logic. In other words, such formats are likely to be able to generate at least some audiovisual content dynamically Such players will, in that sense, have similar processing capabilities to personal computers However, such players and respective storage media will still need to comply with a respective format specification, in order to ensure widespread consumer acceptance The present applicant has determined that, surpnsingly, a significant number of DVD players on the market today do not fully comply with all aspects of the DVD-Video format specification: that is, they are not format-compliant'. While most players will replay most commercially produced DVD movies, more complex DVD content, for example game content, can cause playback errors in some non-compliant players. This is a problem both for DVD authoring companies and DVD player manufacturers, both of whom wish to be able to say their products are fully format compliant.

For example, DVD players that comply with the DVD-Video format specification are expected to have a random number generator function, RND(N), which returns a value v in the range { 1 v N}. However, some manufactures have implemented the RND(N) function to return a value v in the range {0 v (N-I)). Obviously, the latter form of RND function can cause problems, for example if the random number returned is zero, and is used as the divisor in a division operation, the result can be an error or overflow; or, if the result is used in a quiz game to select one question from a group of questions numbered I to 100, and all questions need to be answered before a next level can be reached, the function RND( 100) would never return the value 100 and a player would never be able to access the next level of the game. Obviously, many other problems may arise as a result of a wrongly implemented random number generator function Another problem relates to so-called clamping' in relation to an Add' function of some DVD players According to the DVD- Video format specification, the value of a sixteen-bit GPRM register should increase from a minimum value of 0 to a maximum value of 65535 as a result of addition operations, and should remain clamped' at the maximum value even if further additions occur. For example, the result of the sum (65530 + 20) should be 65535. However, some manufacturers have implemented the addition function so that the register value wraps'; that is, the result of the sum (65530 + 20) is 14.

The present applicant is aware of many other similar problems with various DVD players In general, a non-compliant DVD player may respond unpredictably during DVD playback, which is obviously highly undesirable.

The problem of format non-compliance did not generally arise for VHSvideo, since compliance was very much a matter of ensuring that players exhibited in-format mechanical and electncal characteristics, which are relatively easy to engineer and test for However, the advent of DVD-Video. with its support for interactive functionality, has significantly increased the difficulty of achieving, and indeed testing for, format compliance The present applicants believe that it will become increasingly more difficult to achieve format compliance in new and future generations of technology, as additional features and functionality are accommodated This will invariably mean that more and more players that enter the market place will not be fully format compliant An aim of embodiments of the present invention is to mitigate the aforementioned problems.

According to a first aspect, the present invention provides apparatus for playing audiovisual content, which is stored on a storage medium, the apparatus comprising a processor and a memory storing identification data, which is capable of identifying the apparatus and which is readable by the processor under the control of the content.

The apparatus may accept a removable storage medium, such as an optical disc. For example, the apparatus may be a CD player, a DVD player, a Bluray disc player, an HD-DVD disc player or even a I-JVD player. Alternatively, the apparatus may accept other kinds of storage medium, for example, solid-state memory such as Flash memory, or the like. Additionally, or alternatively, the apparatus may be arranged to receive content from a remote source, via a fixed or wireless connection.

The connection may be a telephone line or a cable, terrestrial or satellite transmission Indeed, the connection may be an Internet connection or a video-on-demand connection, or the like Received information may be stored in a memory, for example a solid-state memory, such as RAM or Flash memory, on a hard disc or written to an optical disc.

The identification data may comprise a manufacturer identity, an apparatus-model identifier, a firmware identifier, or any one or a combination thereof Indeed, any other kind of identification data that can be accessed and used by the processor for the purpose of content reproduction is encompassed.

The use of firmware identification data would be advantageous, since firmware for particular apparatus can be upgraded over time, particularly if problems arise. For example. firmware identification would enable a distinction to be drawn between early apparatus that is not formatcompliant and later apparatus that has upgraded firmware and is format compliant The processor may be arranged to use the identification data to evaluate a conditional operation of the control content A conditional operation might comprise, for example, an IF.. .THEN. . ELSE statement, a CASE statement, a DO. WHILE statement, or equivalent. The result of evaluating the statement might cause some kind of decision, re-direction or branching in the behaviour of the apparatus The content might include plural alternate control paths and the processor may than be arranged to select a control path on the basis of the identification data.

In one embodiment of the invention, plural control paths are provided and one control path is associated with apparatus that is deemed to be formatcompliant and another control path is deemed to be associated with a format-non-compliant apparatus In another embodiment of the invention, one control path is associated with an ability to process a certain kind of content and another control path is associated with an inability to process that content. In yet another embodiment of the invention, one control path is associated with having a nght to process certain content and another control path is associated with having no right to process certain content.

The apparatus may further comprise a memory for storing status data.

The processor, using the identification data, may be arranged to evaluate a status condition operation of the content and modify the value of the status data on the basis of the evaluation.

In one embodiment of the invention, the content is arranged to determine, on the basis of the identification data, whether the apparatus is formatcompliant, for example, by comparison with known non-compliant apparatus. A status condition is then set to indicate whether or not the apparatus is found to be format compliant.

The content may comprise further identification data of one or more kinds of apparatus that are known to be not format compliant with a predetermined format of the audiovisual content The apparatus may be arranged to evaluate format compliance by comparing the identification data of the apparatus with the further identification data of the content.

The apparatus may be arranged to use one control path of the content if the apparatus is not format compliant and a different control path if the apparatus is format compliant.

In general, the apparatus may be arranged so that different content is processed or reproduced depending on the identification data. For example, different control paths may be followed depending on the identification data. Alternatively, or in addition, different audiovisual content may be reproduced depending on the identification data. For example, in a case where the identification data is used to determine whether the apparatus is format compliant, an image may be reproduced which informs the user that the apparatus does not comply with the format. This would encourage the user to return the apparatus to the manufacturer in order to obtain an upgrade.

The apparatus may be adapted to use the identification data to establish whether or not the apparatus complies with a pre-determined format of the audiovisual content.

The identification data preferably cannot be modified under the control of the content. For example, the identification data is stored in a readonly memory.

According to a second aspect, the present invention provides a method of replaying audiovisual content, comprising the steps of programmatically identifying an apparatus used for said replaying step and replaying said content using said identification.

According to a third aspect, the present invention provides a method of authoring audiovisual content including the step of incorporating into the content an operation for accessing and using identification data, which is stored on an associated audiovisual content reproduction apparatus.

According to a further aspect, the present invention provides a data carrier containing audiovisual content, including an operation for accessing and using identification data, which is stored on an associated audiovisual content reproduction apparatus The data carrier may comprise an optical disc, solid state memory, such as RAM or Flash memory, or a hard disc The data carrier may be fixed or removable with respect to the content reproduction apparatus.

According to a still further aspect, the present invention provides a method of determining whether an audiovisual reproduction apparatus is format-compliant with respect to audiovisual content, comprising the steps of.

providing the apparatus with an identification data; and providing audiovisual content, for replay by the apparatus, including means to use the identification data to control an aspect of the playback of the content, which is associated with whether or not the apparatus is formatcompliant Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, of which: Fig. I is a functional block diagram of a DVD player, which has been modified in accord with a preferred embodiment.

Fig. 2 is a flow diagram illustrating a prior art method of using a random number generating

function of a prior art DVD player,

Fig. 3 is a flow diagram illustrating a method of using a random number generating function in accord with an embodiment of the present invention Fig. 4 is a flow diagram illustrating a prior art method of using an Add function with a prior art DVD player; Fig 5 is a flow diagram illustrating a method of using an Add function in accord with an embodiment of the present invention; and Fig. 6 is a functional diagram of a audiovisual content authoring system that can be used for authoring audiovisual content in accord with embodiments of the present invention.

Embodiments of the present invention will now be described with reference to the block diagram in Figure 1. The diagram illustrates the functional components of a typical DVD player, which, as will be described, has been adapted to operate in accord with embodiments of the present invention According to Figure 1, a typical DVD player comprises a navigation engine 100 The navigation engine 100 comprises a central controller, or CPU 105, which is arranged to co-ordinate and control all other components and the operation of the DVD player. The CPU 105 operates according to control program instructions, which are stored in a non-volatile program memory 107 The control program is typically known as the DVD player firmware 109.

The navigation engine 105 also comprises a remote interface 110 for receiving user input signals from a remote controller (not shown). The CPU 105 interprets the user input signals as user instructions, which influence the flow of the control program 109 Furthermore, the navigation engine 105 comprises a random access memory (RAM) 112.

The RAM 112 is used dunng DVD player operation to store system-use parameter (SPRM) values and general-use parameter (GPRM) values, in respective SPRM memory registers 114 and GPRM memory registers 116. SPRM registers 114 typically store information such as language code, audio and subpicture settings, parental level settings and the like. A number of SPRM registers can only be used to determine the state of the DVD player and are read-only during DVD playback. Other SPRM registers, for example relating to user-selected audio stream, camera angle or subpicture (subtitle) stream, can be modified indirectly by specific instructions, for example which cause playback to move to a different location on the DVD. SPRM values cannot be set directly by DVD playback command instructions (discussed in more detail below).

GPRM registers can be used for various purposes, for example keeping score in a DVD game, storing viewer responses, tracking what sections of disc have been seen and acting as temporary stores for simple mathematical or Boolean operations, which are supported by the DVD player. In other words, GPRM registers are usable by playback instructions and can be set directly during DVD playback.

The DVD player also comprises a deck 120, which controls the rotation of a loaded DVD disc 122 and the movement of disc read and write heads; although, herein, only read-related components will be described. The deck 120 includes a read head 124, and associated actuators (not shown), and a pre-amplifler 126, for amplifying and conditioning signals that are read from the DVD disc 122. The deck 120 also includes a deck controller 128, for controlling the operation of the deck The deck controller 128 is controlled by signals from the CPU 105.

The DVD player also includes a presentation engine 130. The presentation engine 130 comprises a stream processor 132, for processing a data stream as it is read from the disc 122, via the pre-amplifier 126. As is well known in the art, this processing step includes demodulating the stream, unscrambling the stream, applying an error-correcting algorithm, dcmultiplexing the stream into vanous video, audio, subpicture and presentation control information streams and decoding the respective streams into their native formats The presentation engine 130 further compnses a formatter 134, which receives the processed streams and, under the control of the CPU 105, selectively generates final audio and video output signals for respective video and audio playback equipment (not shown).

A DVD-Video optical disc contains audiovisual content, which typically comprises two kinds of data - presentation data and navigation data - that arc encoded into the vanous streams. The presentation data generally includes the audiovisual content (for example video, audio, subpicture, and still images) and instructions for where to find, and how to access and replay, that content. The navigation data generally provides the means for accessing the presentation data. The navigation data typically defines a user interface, for example including one or more menus and command instructions that are used to provide rudimentary interactivity and facilitate branching, for example, depending on user input.

During operation, at a conceptual level, a DVD player reads a DVD disc 122 and extracts and separates the audiovisual content into navigation and presentation data. Typically, a default operation, specified by the navigation data, is to display a top-level user menu, from which a user can control the set-up and subsequent behaviour of the DVD. The CPU 105 receives respective signals from the remote controller (not shown), and interprets them on the basis of navigation data definitions.

For example, the user instruction can be a direct request to replay particular content, for example a movie. Alternatively, the user instruction may be an input into an algorithm, whereby the output of the algorithm dictates which audiovisual content to replay. For example, the user instruction may be one of several possible responses to a question, in a quiz game. The algorithm would then take the response, compare it to a stored correct response, and replay a Correct Answer' content or an Incorrect Answer' content.

According to embodiments of the present invention, the DVD player includes a player identity (ID) data 140, which is embodied as a value, or values, stored in the DVD player. In a preferred embodiment, the ID data 140 comprises three portions; a manufacturer identity 142, a player identity 144 and a firmware version identity 146, as illustrated in Fig. la.

The ID data 140 comprises read-only data and, in this respect, is similar to the read-only SPRM registers, which store DVD player status information. Therefore, the ID data 140 can be read, but not modified, in response to command instructions from a DVD.

There are a number of ways of storing ID data on the DVD player. For example, the DVD player could be manufactured, with the information being written in read only memory. This method, however, would suffer the disadvantage that the information could not be updated, in the event the player were modified, for example by updating the firmware in the known manner. Therefore, according to embodiments of the present invention, the ID data 140 is stored in non-volatile, re- writable memory, for example the non-volatile program memory 107 in which the firmware 109 is stored. From there, the ID data 140 can be read directly by the CPU 105 in response to a command instruction, In a preferred embodiment, however, the ID data 140 is stored in RAM 112, in response to one or more firmware instructions, which cause the CPU 105 to wnte the respective values into the RAM 112 as part of a power-on sequence of the DVD player. The values are stored in the RAM 112 in one or more read-only registers. The registers can be existing, otherwise unused, registers or additional registers. In any case, the values stored in the registers can be accessed and evaluated by the CPU 105 on the basis of command instructions. That is, the DVD player's ID data 140 is accessible under the control of the navigation data, which is stored on a DVD disc 122.

According to a preferred embodiment, each of the three ID data portions 142, 144 and 146 are integer numbers written into a separate SPRM register 114. Each manufacturer would be assigned a unique manufacturer identity. Each manufacturer would then allocate each DVD player with a unique player identity and each version of respective firmware with another unique firmware identity.

It is already commonplace for firmware to be identified by a version number However, the firmware version code is currently not readable or usable during playback of a DVD under the control of the navigation data.

An advantage of the preferred embodiment is that the ID data 140 can be updated automatically whenever the firmware is updated According to the present embodiment, advantageously, the CPU 105 can access and use the ID data 140 in response to particular command instructions, for example standard SPRM register read instructions, as will be described in more detail hereinafter.

As already described, one known problem with some DVD players is how the respective RND(N) function has been implemented. Format compliant DVD players return a random number in the range (1 v N}, whereas non-formatcompliant DVD players can return a random number in the range{0vN-1}.

This problem will now be illustrated in the context of a simple scenario, in which a DVD player needs to generate a random number for use in a DVD quiz game.

The flow diagram in Figure 2 illustrates the flow of an extremely simple, exemplary DVD quiz game, which is implemented using a prior art DVD player. The game is controlled by simple program logic, which is embodied in command instructions on the DVD, and which are received and executed by the CPU in the usual fashion. In a first step 200, the user initiates playback of the DVD in order to play the DVD game. In step 205, the DVD player generates a random number vi, using its random number generating function (vi = RND(N)), and stores the value v I in a first GPRM register.

For any pnor art DVD player, the exact nature of the RND function is unknown and impossible to predict, during DVD playback, since there is no way to know how the function has been implemented.

In step 210, the DVD player selects, using the value vi, and displays a first question, for example embodied as a still image and a simple user input menu providing several possible answers.

If the random number function has not been correctly implemented, it is possible that game play will not behave as expected by thc authors of the game For example, one or more questions may never be presented to the user. In step 215, the DVD player: receives a user input signal representing the user's answer to the question; interprets the signal, in accord with respective game logic; stores the result in a second GPRM register; and compares the first and second GPRM registers to see if the stored values match. If the values match, in step 220, the answer is deemed correct and the next question is displayed. If the information differs then, in step 225, the answer is deemed incorrect, the DVD player displays a "Wrong Answer" image and the quiz ends It will be appreciated that, while the foregoing example of a DVD game is extremely simplistic, it illustrates one potential scenario when the implementation of the RND fUnction can have an adverse impact on whether or not a DVD game plays correctly. It will be clear that more complex DVD games, or other DVD content, could also be adversely affected.

The flow diagram in Figure 3 illustrates the same exemplary DVD quiz game, which has been adapted to be played on a DVD player according to the preferred embodiment of the present invention. In step 300, the user initiates playback of the DVD game as in the previous example. In step 305, the DVD player compares the identities of DVD players that are known to be non-format- compliant, in respect of their RND function, with the stored ID data 140 of the DVD player. This companson step can comprise one, several or many such comparisons, depending on how many DVD players are known to be non- compliant. For example, if there are thirty DVD players that are known to have a defective RND function, then the compare step may compnse thirty independent comparisons. Each comparison is embodied in one or more associated command instructions, which cause the Cpu 105 to evaluate the ID data 140, which is stored in RAM 112. The outcome of the or each comparison is to set a third, Compliance, GPRM register to 1, in step 310, if the DVD player ID is found to match a non-compliant identity; or otherwise leave the register value as 0 (which is the default value) Next, in step 315, the DVD player executes a conditional command that evaluates the third, Compliance GPRM register. If the register value is 0, indicating that the RND function of the player is compliant, then, in step 320, the DVD player generates a random number v2 using its random number generating function (v2 = RND(N)). On the other hand, if the value in the third GPRM register is I, indicating that the RND function is non- compliant, then the program flow redirects and, in step 325, the DVD player generates a random number using a modified random number generating function (v2 = (RND(N) + I)). The modified function forces the value of v2 to be in the correct range { 1 v N} rather than in the incorrect range {0 v N-i}. In either case, the resulting random number is stored in a first GPRM register.

In step 330, the DVD player selects, using the value v2, and displays a first question. In step 335. the DVD player: receives a user input signal representing the user's answer to the question, interprets the signal, in accord with respective game logic; stores the result in a second GPRM register; and compares the first and second GPRM registers to see if the stored values match. If the values match, the answer is deemed correct and the process redirects to step 315, via which the next question is displayed in step 330. If the information differs then, in step 340. the answer is deemed incorrect, the DVD player displays a "Wrong Answer" image and the quiz ends.

It will be appreciated that, should the need arise, the foregoing procedure may be adapted to cope with cases where there are three or more variants in the way a random number is generated.

The flow diagram in Figure 4 illustrates a simple, exemplary algorithm,which may be used on a DVD disc, to add individual game scores to a Total. The game, for example a quiz game. is repetitively played until the Total reaches a high score level of 65,535 Each game has a range of possible scores from 0 to 10,000; for example, depending on how well a player performs in answering a senes of questions. The player wins when the Total meets or would exceed 65,535 According to Figure 4, in step 400, under the control of the navigation data command instructions, the player plays the DVD game and achieves a Score. In step 405, the Score is added to a Total In step 410, the Total is compared to the high score level of 65,535. In step 415, if the Total has reached the high score level, then a You Win' image is displayed and the game ends On the other hand, if the Total is less than 65,535, then the program branches to step 400, from where the player can play the game again. If the game were a quiz, for example, it would be expected that different questions would be asked each time the game was played.

In this foregoing example, the algorithm will work as long as the Add' function of the DVD player is implemented correctly. A correct implementation means that, in step 405, when the value reaches or would exceed 65,535 it remains clamped at 65,535. If, on the other hand, the value does not clamp, but rather it wraps' around, back to zero, the game only ends if the exact value of 65,535 is achieved, which may never be the case. It is likely that a game author, referring to the DVD-Video format specification, would expect the Add function to clamp at 65,535 and author a product on this basis. In this case, non-compliant DVD players may not execute the product correctly.

A modified algorithm, according to an embodiment of the present invention, which uses player ID data, will now be described with reference to the flow diagram in Figure 5 According to Figure 5, in step 500, under the control of navigation data command instructions, the DVD player compares the identities of DVD players that are known to be non- compliant, in respect of their Add' function, with the stored ID data 140 of the DVD player, by causing the CPU 105 to evaluate the ID data 140, which is stored in RAM 112. The comparison step can comprise one, several or many such comparisons, depending on how many DVD players are known to be non-format-compliant. The outcome of the or each comparison is, in step 505, to set a third, Compliance GPRM register to I if the DVD player ID matches a non-format-compliant identity, or leave the default register value as 0.

Next, in step 510, the player plays the DVD game and achieves a Score In a step 515, the DVD player evaluates the value of the third GPRM register. If the value is 0, indicating the DVD player is format-compliant with respect to the Add' function, then, in step 520, the score is simply added to the Total. If, however, the value is I, indicating that the DVD player is non-compliant, then the program branches and, in step 525, a modified Add' function is applied. The modified Add' function has the form.

IF (65,535 - Score)> (Total) THEN (Total = Total + Score) ELSE (Total = 65,535) The first line of the function is a pre-check, which, in effect, determines whether (Score + Total) exceeds 65,535. If the pre-check determines that the result would not exceed 65,535 then, in the second line of the function, the Score is added to the Total in the normal way. If, however, the pre-check determines that the result would exceed 65,536, which would cause the result of the Add' operation to wrap around, than the third line of the formula causes the Total to equal 65,535. In other words, the formula forces the value of Total to clamp' to 65,535 for any Total that equals or would exceed 65,535. The function, in effect, produces the same result as a DVD player that is format compliant.

In step 530, the DVD player determines whether the Total is equal to 65, 535. If it is, then, in step 535, a "You Win" still image is displayed and game ends. Otherwise, the game redirects to step 510, from where the player can replay the game in order to attempt to reach the high score.

It is anticipated that, on occasion, a DVD player may arise that is noncompliant and that it may be impossible, or at least impractical, to provide a workaround solution, of the kind illustrated in Fig. 3 or Fig. 5. A player ID data could be used to identify such players, by reference to respective player ID information that is stored on the player. In accord with embodiments of the present invention, a practical solution may be to author and store an information image on the DVD and use the navigation data command instructions to evaluate the player ID data and display the image if a defective DVD player is encountered. For example, the still image may include the text message: "Your DVD player is defective and cannot play this DVD. Please contact your manufacturer and request an upgrade." Manufacturers are sometimes able to update the firmware of a DVD player in order to overcome problems that are encountered. Using an image to deliver a message to a user is an efficient way of informing the user that their DVD player would benefit from an upgrade Once DVD players and the like are configured to contain ID data, which can be accessed and used under audiovisual content control, then authors of the audiovisual content can begin to take advantage of the ability to evaluate whether a respective player is format compliant. Authors are already familiar with wnting navigation data, which provides interactive capabilities in DVD playback, and it would not be a significant overhead to add the ability to evaluate whether or not a DVD player is format compliant Indeed, it would appear to be a distinct advantage for authors to be able to say that their products can play even on non-compliant players.

Embodiments of the present invention find application in areas unrelated to format specifications and format compliance. For example, the ability to determine the identity of a DVD player provides the opportunity for an author of DVD to generate a DVD in which there are certain kinds of content that can only be replayed on certain kinds of DVD players. One example is a DVD player that can replay a certain kind of content, for example MP3 audio content, which is not supported by all mainstream DVD players. In that case, the author may generate two different menu screens and command instructions to evaluate the player ID data to establish whether the player is known to play that certain kind of content. If the player cannot play the content, then a respective menu, which does not have an option to replay the content, is displayed If, on the other hand, it is established that the player can play the content, then the player displays an alternative menu, which has an option for the user to select and replay the content. In this example, the issue of whether or not the player can replay the content is unrelated to format-compliance.

In general, as formats become more complex, it is anticipated that audiovisual content players will evolve and support more and more features, some of which are format-specific and others of which maybe, for example, manufacturer specific. Use of an ID data in a player will enable authors to generate audiovisual content that can establish the capabilities of respective players, in order to present a user appropriate options for playback of the content.

A basic audiovisual authoring system is illustrated in the diagram in Fig. 6. Fig 6 shows an exemplary authoring apparatus as may be employed in preferred embodiments of the present invention The authonng apparatus includes a computing platform such as a client-server computer system, or a stand-alone personal computer, 630 Optionally, raw audio and video data are received, such as through a camera 610 and a microphone 620, or are provided from other sources such as a file storage device 625, or are created within the authoring apparatus such as by image and sound capture and creation software. The raw content data may include video clips, audio clips, still picture images, icons, button images and other visual content to be presented onscreen. The content is suitably in the form of MPEG, JPEG or bitmap encoded files, but may take any suitable format Original audiovisual data can take any form such as a movie, or a company presentation, or a quiz game, amongst many other possibilities The computer 630 acting as the authoring apparatus creates the desired audiovisual product using the features that have been described herein. The computer 630 writes the audiovisual product 645 onto a storage medium such as a hard disk drive within the computer 630 or onto an optical disk 640.

Authoring audiovisual products, for example products that comply with the DVD-Video format specification, can be a complicated task. However, the task is simplified by using one of the many authoring products that are commercially available, for example ScenanstTM (from Sonic SolutionslM), DVD Studio Pr0TM (from Apple), DVD EXTRA - I'M (from ZOOtech Limited).

Pinnacle Studio or EncoreTM (from AdobeTM). An advantage of using one or more of these software products is that it is not necessary to understand the DVD-Video format specification in order to produce an audiovisual product, since each product is able to assemble high-level design information and audiovisual asset content, which is provided by an author, into format-compliant audiovisual content.

The skilled person will appreciate that aspects and embodiments of the present invention are not in any way limited to application with current DVD players. Rather, the principles set forth herein arc far more broadly applicable to any form of apparatus, player or equipment for replaying audiovisual content The audiovisual content may be stored on removable media, such as an optical disc or on removable or fixed media, such as Flash memory or hard disc. In addition, the content may onginate on purchased media or be downloaded, for example, via the Internet, via terrestnal, cable or satellite broadcast channels or distributed in a point-to-point system such as video-on-demand, or the like. It is expected that, in the near term, embodiments of the present invention will find application at least in DVD-Video, Blu-ray and HD-DVD optical disc players.

While embodiments of the present invention have been described with reference to a DVD player apparatus, for example as illustrated in Figure 1, wherein the presentation and navigation engines are typically realised as hardware components, it will be appreciated that the principles set forth herein equally apply to a computer based DVD-Video playback arrangement, comprising a computer system having a DVD-ROM drive, a DVD player software application program and associated driver programs In a typical computer based DVD-Video playback arrangement, the DVD-ROM dnve acts as a deck and the functional components of the presentation engine and the navigation engine are realised as software dnvers and applications, which are processed by the CPU of the computer and, possibly also, by dedicated graphics and sound processing hardware, in order to provide DVD-Video playback capability In a computer based DVD playback system, interaction with the DVD player functions is typically via keyboard and mouse control rather than via a remote controller In any event, references herein to apparatus' apply equally to dedicated hardware and computer-based solutions.

Claims (16)

1. Apparatus for playing audiovisual content, which is stored on a storage medium, the apparatus comprising a processor and a memory storing identification data, which is capable of identifying the apparatus and which is readable by the processor under the control of the content.

2 Apparatus according to claim 1, wherein the processor is arranged to use the identification data to evaluate a conditional operation of the content.

3. Apparatus according to claim 1 or claim 2, wherein the content includes plural alternate control paths and the processor is arranged to select a control path on the basis of the identification data

4 Apparatus according to any one of the preceding claims, further comprising a memory for storing status data.

Apparatus according to claim 4, wherein the processor, using the identification data, is arranged to evaluate a status condition operation of the content and modify the value of the status data on the basis of the evaluation.

6 Apparatus according to any one of the preceding claims, wherein the content compnses further identification data of one or more kinds of apparatus that are known to be not format compliant with a pre-determined format of the audiovisual content.

7 Apparatus according to claim 6, arranged to evaluate format compliance by comparing the identification data of the apparatus with the further identification data of the content

8 Apparatus according to claim 7, arranged to use one control path of the content if the apparatus is not format compliant and a different control path if the apparatus is format compliant.

9. Apparatus according to any one of the preceding claims, wherein different content is processed or reproduced depending on the identification data

10. Apparatus according to any one of the preceding claims, adapted to use the identification data to establish whether or not the apparatus complies with a pre-determined format of the audiovisual content

11 Apparatus according to any one of the preceding claims, wherein the identification data cannot be modified under the control of the content.

12. Apparatus according to any one of the preceding claims, wherein the identification data is stored in a read-only memory.

13. A method of replaying audiovisual content, comprising the steps of programmatically identifying an apparatus used for said replaying step and replaying said content using said identification.

14. A method of authoring audiovisual content including the step of incorporating into the content an operation for accessing and using identification data, which is stored on an associated audiovisual content reproduction apparatus.

A data carrier containing audiovisual content, including an operation for accessing and using identification data, which is stored on an associated audiovisual content reproduction apparatus.

16. A method of determining whether an audiovisual reproduction apparatus is format-compliant with respect to audiovisual content, comprising the steps of providing the apparatus with an identification data; and providing audiovisual content, for replay by the apparatus, including means to use the identification data to control an aspect of the playback of the content, which is associated with whether or not the apparatus is format-compliant.